Hermit Crab Water: Fresh Water, Salt Water, and Why Your Crabs Need Both
Water is one of the most important parts of a hermit crab habitat, and one of the most commonly misunderstood.
Many new owners are surprised to learn that hermit crabs need access to both fresh water and salt water every day. Each one serves a different purpose, and neither can replace the other.
Getting this right is simpler than it sounds.
Why Do Hermit Crabs Need Two Water Pools?
Although land hermit crabs spend most of their lives on land, they still depend on both fresh water and salt water.
In the wild, hermit crabs move between fresh water sources and the ocean. Offering both pools in your crabitat lets them choose what they need, when they need it.
Neither pool replaces the other. Both should always be available.
How Deep Should the Water Be?
Both pools should be deep enough for your largest crab to fully submerge if it chooses.
Some crabs take a quick drink. Others soak for several minutes. Either is normal.
Just as important, every pool needs an easy way out. Rocks, cholla wood, plastic mesh, and other textured surfaces all make good ramps, especially for smaller crabs.
Deep water is safe when your crabs can climb in and out on their own. If a surface feels slippery to you, it's probably slippery for your crabs too.
Can I Use Tap Water?
Not without treating it first.
Most tap water contains chlorine, chloramines, or both. These chemicals make drinking water safe for people, but they aren't safe for hermit crabs.
Always treat tap water with a quality water conditioner, like Prime Water Conditioner, before adding it to your crabitat. Use one that removes both chlorine and chloramines, not just chlorine alone.
How Do You Make Salt Water?
Salt water should always be mixed using a marine salt mix made for saltwater aquariums, like Instant Ocean Marine Salt.
Table salt, sea salt from the grocery store, Himalayan salt, and freshwater aquarium salt are not suitable alternatives to a marine salt mix.
Follow the mixing directions on the package and always use treated fresh water when preparing salt water.
Can Hermit Crabs Drown?
Healthy hermit crabs can safely use deep water pools as long as they have a way to climb back out.
That's why every pool needs a ramp or textured surface they can grip.
The goal isn't shallow water. The goal is safe access.
Do Hermit Crabs Need Sponges?
No.
Sponges are often sold alongside hermit crab supplies, but they aren't necessary. A properly designed water pool with a safe ramp gives your crabs everything they need to drink and soak on their own.
Common Water Mistakes
A few mistakes come up again and again with new keepers.
Using untreated tap water is one of the most common. Always treat tap water before adding it to your crabitat.
Another is using table salt or grocery store sea salt instead of a marine salt mix. They aren't the same thing and shouldn't be used instead.
The last is making the pools too shallow out of fear of drowning. Healthy hermit crabs can safely use deep pools as long as they have an easy way to climb back out.
How Often Should You Change the Water?
Replace both pools regularly to keep them clean. If sand, food, or waste gets in, change the water sooner.
Clean water encourages normal drinking and soaking behavior, and it's one of the easiest parts of a healthy crabitat routine.
Water Is Part of a Healthy Crabitat
Fresh water and salt water aren't optional.
Keep both pools clean, treat your water properly, and make sure your crabs can safely climb in and out.
It's a simple part of your routine, but one that supports your hermit crabs every single day.
Ready to set up your water pools? Shop Instant Ocean Marine Salt and Prime Water Conditioner to get started.
Related Guides
- Hermit Crab Habitat: How to Build a Healthy Crabitat
- Hermit Crab Molting: Signs, Stages & How to Help Your Crab Survive